1. Field of the Invention
The invention relates to licensing software, and more particularly, to licensing software electronically in a network environment.
2. Description of the Related Art
Most software vendors currently favor licensing as the preferred method of distributing software. Licensing software provides the vendor with a certain amount of control which may be used to the vendor's advantage. For example, licensing software allows the vendor to prohibit unauthorized usage of the software that might facilitate unauthorized copying. In addition, licensing provides an advantageous method of providing and billing for software. Through licensing, the vendor may sell several identical copies of the same software and charge the buyer for each copy.
Licensing schemes have been adapted for the network environment as well as the individual personal computer. In a network environment, such as a client-server network, multiple users may access the same copy of a particular application. Consequently, the vendor can charge the network owner not for the number of copies installed on the network, but for the number of users having access to the software.
Software is conventionally licensed using an agreement between the vendor and the user or administrator. The agreement is typically either a conventionally signed contract or a "shrink wrap" agreement attached to the packaging for the software, to which the licensee acknowledges agreement by opening the package.
Although traditional and shrink wrap licensing are more or less applicable to individual systems, they are not well-suited to the network environment. Both traditional and shrink wrap licensing schemes are difficult to enforce on a network where several users have access to the software. Consequently, various electronic systems have been devised for controlling access to software on a network.
Electronic licensing typically comprises providing a set of criteria under which a request for an application from the server should be granted. One common licensing system uses a fixed set of licenses controlled by a license server. The license information is maintained in a license database, along with information regarding which applications are in use and how many units are still available. The information in the database may be encrypted to prevent forgeries. When an application is desired, the application commences running. Code embedded in the application initially requests a license from the server to facilitate the execution of the application. The server checks the database of licenses, and if the appropriate licenses are available, grants the request. As requests are received and licenses granted, the relevant information is logged into a file to track usage of the various applications.
If a license is not available, the client contacts another server to find the appropriate license. The client in the conventional system has the responsibility to obtain licenses from the various servers, and the individual servers provide resources at the client's request. To facilitate such licensing, the application typically includes a library of programs designed to contact the server, request a license, and track the resulting license.
Although such a licensing system provides some security against unauthorized usage of applications, it suffers several drawbacks. For example, the number of programs required for the client to request and maintain licenses occupies a significant portion of the client's limited memory resources. Further, a conventional licensing system stores most of the licensing information in the client's memory. Consequently, in the event of a client crash, the licensing information is lost and difficult to reconstruct.
Conventional licensing systems also suffer limited scalability. When a call is made to a server, all of the execution occurs on each individual server for any particular call. Similarly, if a license is located on a particular machine, all execution necessary to operate on that license occurs on that machine. Consequently, a central server containing most of the licenses available on a particular network may be overworked while other, more local server resources remain idle. Similarly, if any particular server crashes or otherwise becomes unavailable, none of the licensing information associated with that server can be accessed by clients, even if other servers are operating.
In addition, conventional licensing systems rely on code embedded in the application to establish the licensing attributes. Code is placed in the application which interprets information received from the server to establish licensing parameters. Because the behavior of the license is not established until after the request has been made and the license obtained, the user cannot read the license terms prior to the request. Moreover, this system lacks flexibility. To change the licensing terms, the code in the application must be revised.
An electronic software licensing system is thus needed which overcomes the shortcomings of the prior art.